Public policies set the context within which HIV prevention, identification and treatment occur. For example, state policies regarding needle exchange affect transmission rates among injecting drug users and policies on names reporting affect HIV testing behavior among individuals concerned with a potential breach in confidentiality. At the national and international levels, funding allocated for HIV care affects the numbers of individuals who receive effective treatment and can live prolonged and healthier lives. The Policy Core determines the consequences of public policies on HIV identification, prevention and treatment of HIV in local, state, national and international settings and provides this information to provide public health and governmental leaders with the evidence base necessary for well-informed policy-making. The specific aims of the Policy Core are: 1. Science: Identifying and promoting research on the determinants and consequences of public policies on HIV identification, prevention, and treatment of HIV disease, in both domestic and international settings; 2. Science: Applying policy research methods, such as cost effectiveness analysis (CEA) and geographic information systems approaches (CIS), to projects related to the Center's key scientific themes; 3. Networking: Convening policy makers, HIV investigators, and community stakeholders to identify and address critical HIV policy issues and identify the types of data needed to inform such issues; 4. Capacity Building: Enhancing the skill of our research partners to apply policy methods (e.g., CEA and GIS) to their HIV projects and to increasing the ability of our community partners to evaluate their prevention programs;and, 5. Capacity Building: Disseminating policy-relevant findings from intervention and policy research projects in different formats to domestic and international audiences.